This is one of the less common side formations. If Black plays next at a the corner co-ordination of the resulting 'sub-orthodox formation' is reasonable (not great, perhaps, compared to the orthodox fuseki).
Assuming White enters at here, the co-ordination isn't brilliant if Black plays, for example, the pincer b. Black's chances of a framework on the upper side are limited by what White might do with the shoulder hit at c next. Black at b looks like the right type of idea with a 4-4 point in the right-hand corner.
Cho Chikun's play, in a number of his games, is to press with . This then assumes that the right-hand corner can take care of itself. In playing the press one has to bear in mind some large-scale variations leading to a pushing battle. See pushing battles in joseki 5.
Thinking of the other arrangement, we get a formation rare in pro games (tried out a few times by Sakata).
White can easily ignore this side.
Easy shoulder hit reduction
The reason is that keeps the side territory down, even if Black uses
and
to build up a framework.